Packaged terminal air conditioner unit

ABSTRACT

A packaged terminal air conditioner unit includes a casing. A compressor, a reversing valve and an ejector of the packaged terminal air conditioner unit are positioned within the casing. The ejector is configured for drawing vapor refrigerant into a flow of liquid refrigerant. An exterior heat exchanger and an interior heat exchanger are also positioned within the casing. The interior heat exchanger has a first stage and a second stage.

FIELD OF THE INVENTION

The present subject matter relates generally to heat pump systems, such as packaged terminal air conditioner units, and sealed systems for the same.

BACKGROUND OF THE INVENTION

Certain packaged terminal air conditioner units include a sealed system for chilling and/or heating air. The sealed systems include various components for treating a refrigerant in order to cool or heat air. The sealed system components are generally positioned within a casing that can be mounted within a wall or window of an associated building. Due to space constraints within the casing, selection of sealed system components for packaged terminal air conditioner units can be limited to relatively small components.

Packaged terminal air conditioner units are frequently classified and sold by efficiency. Customers generally prefer efficient packaged terminal air conditioner units because small improvements in heating and cooling efficiency can provide a significant reduction in utility bills. Energy efficiency in packaged terminal air conditioner units is generally a function of compressor size and efficiency, heat exchanger size, design and airflow and fan design among other factors. However, high efficiency compressors are typically very expensive, and large heat exchangers may not fit within the limited space available in the casing of a packaged terminal air conditioner unit.

Accordingly, a packaged terminal air conditioner unit with features for assisting with increasing an efficiency of the packaged terminal air conditioner would be useful. In particular, a packaged terminal air conditioner unit with features for assisting with increasing an efficiency of the packaged terminal air conditioner without requiring a high efficiency compressor and/or a large heat exchanger would be useful.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a packaged terminal air conditioner unit with a casing. A compressor, a reversing valve and an ejector of the packaged terminal air conditioner unit are positioned within the casing. The ejector is configured for drawing vapor refrigerant into a flow of liquid refrigerant. An exterior heat exchanger and an interior heat exchanger are also positioned within the casing. The interior heat exchanger has a first stage and a second stage. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In a first exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor is positioned within the casing. The compressor is operable to increase a pressure of a refrigerant. An interior heat exchanger is positioned within the casing. The interior heat exchanger has a first stage and a second stage that are separate from each other. An exterior heat exchanger is positioned within the casing opposite the interior heat exchanger. A phase separator is positioned within the casing. The phase separator is configured for separating liquid refrigerant from vapor refrigerant. A reversing valve is positioned within the casing. The reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to the exterior heat exchanger or the second stage of the interior heat exchanger. A supply conduit extends between the exterior heat exchanger and the phase separator. An ejector is coupled to the supply conduit. A first distribution conduit extends between the first stage of the interior heat exchanger and the ejector. A second distribution conduit extends between the exterior heat exchanger and the first stage of the interior heat exchanger. A connection conduit extends between the phase separator and the second stage of the interior heat exchanger. A bypass conduit extends from the phase separator around the second stage of the interior heat exchanger.

In a second exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing that extends between an exterior side portion and an interior side portion. A compressor is positioned within the casing. The compressor is operable to compress a refrigerant. An interior heat exchanger is positioned within the casing at the interior side portion of the casing. The interior heat exchanger has a first stage and a second stage that are separate from each other. An exterior heat exchanger is positioned within the casing at the exterior side portion of the casing. A reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. A phase separator is positioned within the casing. The phase separator is configured for separating liquid refrigerant from vapor refrigerant. An ejector is positioned within the casing. The packaged terminal air conditioner unit is configured such that, in a cooling mode, a flow of liquid refrigerant from the exterior heat exchanger flows through the ejector and the ejector draws vapor refrigerant from the first stage of the interior heat exchanger into the flow of liquid refrigerant and a combined flow of liquid and vapor refrigerant flows from the ejector to the phase separator. Vapor refrigerant from the phase separator flows around the second stage of the interior heat exchanger to the compressor and liquid refrigerant from the phase separator flows to the second stage of the interior heat exchanger in the cooling mode. The packaged terminal air conditioner unit is also configured such that, in a heating mode, refrigerant from the second stage of the interior heat exchanger flows through the phase separator and the ejector to the first stage of the interior heat exchanger.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit according to an exemplary embodiment of the present subject matter.

FIGS. 2 and 3 provide schematic views of components of a sealed system for a packaged terminal air conditioner unit according to an exemplary embodiment of the present subject matter.

FIGS. 4 and 5 provide schematic views of components of a sealed system for a packaged terminal air conditioner unit according to another exemplary embodiment of the present subject matter.

FIGS. 6 and 7 provide schematic views of components of a sealed system for a packaged terminal air conditioner unit according to an additional exemplary embodiment of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit 100 according to an exemplary embodiment of the present subject matter. Packaged terminal air conditioner unit 100 is operable to generate chilled and/or heated air in order to regulate the temperature of an associated room or building. As will be understood by those skilled in the art, packaged terminal air conditioner unit 100 may be utilized in installations where split heat pump systems are inconvenient or impractical. As discussed in greater detail below, a sealed system 120 of packaged terminal air conditioner unit 100 is disposed within a casing 110. Thus, packaged terminal air conditioner unit 100 may be a self-contained or autonomous system for heating and/or cooling air.

As may be seen in FIG. 1, casing 110 extends between an interior side portion 112 and an exterior side portion 114. Interior side portion 112 of casing 110 and exterior side portion 114 of casing 110 are spaced apart from each other. Thus, interior side portion 112 of casing 110 may be positioned at or contiguous with an interior atmosphere, and exterior side portion 114 of casing 110 may be positioned at or contiguous with an exterior atmosphere. Sealed system 120 includes components for transferring heat between the exterior atmosphere and the interior atmosphere. For example, sealed system 120 includes a compressor 122, an interior heat exchanger or coil 124 and an exterior heat exchanger or coil 126.

Casing 110 defines a mechanical compartment 116. Sealed system 120 is disposed or positioned within mechanical compartment 116 of casing 110. A front panel 118 and a rear grill or screen 119 are mounted to casing 110 and hinder or limit access to mechanical compartment 116 of casing 110. Front panel 118 is mounted to casing 110 at interior side portion 112 of casing 110, and rear screen 119 is mounted to casing 110 at exterior side portion 114 of casing 110. Front panel 118 and rear screen 119 each define a plurality of holes that permit air to flow through front panel 118 and rear screen 119, with the holes sized for preventing foreign objects from passing through front panel 118 and rear screen 119 into mechanical compartment 116 of casing 110.

Packaged terminal air conditioner unit 100 also includes a drain pan or bottom tray 138 and an inner wall 140 positioned within mechanical compartment 116 of casing 110. Sealed system 120 is positioned on bottom tray 138. Thus, liquid runoff from sealed system 120 may flow into and collect within bottom tray 138. Inner wall 140 may be mounted to bottom tray 138 and extend upwardly from bottom tray 138 to a top wall of casing 110. Inner wall 140 limits or prevents air flow between interior side portion 112 of casing 110 and exterior side portion 114 of casing 110 within mechanical compartment 116 of casing 110. Thus, inner wall 140 may divide mechanical compartment 116 of casing 110.

Packaged terminal air conditioner unit 100 further includes a controller 146 with user inputs, such as buttons, switches and/or dials. Controller 146 regulates operation of packaged terminal air conditioner unit 100. Thus, controller 146 is in operative communication with various components of packaged terminal air conditioner unit 100, such as components of sealed system 120 and/or a temperature sensor, such as a thermistor or thermocouple, for measuring the temperature of the interior atmosphere. In particular, controller 146 may selectively activate sealed system 120 in order to chill or heat air within sealed system 120, e.g., in response to temperature measurements from the temperature sensor.

Controller 146 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of packaged terminal air conditioner unit 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 146 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

FIGS. 2 and 3 provide schematic views of components of a sealed system 200 for a packaged terminal air conditioner unit according to an exemplary embodiment of the present subject matter. Sealed system 200 may be used with or in any suitable packaged terminal air conditioner unit. For example, sealed system 200 may be used in packaged terminal air conditioner unit 100 (FIG. 1) as sealed system 120. Sealed system 200 is shown operating in a cooling mode in FIG. 2, and sealed system 200 is shown operating in a heating mode in FIG. 3. The unlabeled arrows in FIGS. 2 and 3 indicate the direction of refrigerant flow within adjacent conduits or piping of sealed system 200 in the cooling mode and heating mode, respectively.

Sealed system 200 generally operates in a heat pump cycle. Sealed system 200 includes a compressor 210, an interior heat exchanger or coil 212 and an exterior heat exchanger or coil 214. As is generally understood, various conduits may be utilized to flow refrigerant between the various components of sealed system 200, as discussed in greater detail below. Thus, e.g., interior coil 212 and exterior coil 214 may be between and in fluid communication with each other and compressor 210 via suitable tubing or piping.

As may be seen in FIGS. 2 and 3, interior coil 212 is a split coil or heat exchanger and includes two separate or discrete stages, a first coil or stage 250 and a second coil or stage 252. Interior coil 212 may be formed in any suitable manner to include first and second stages 250, 252 of interior coil 212. For example, first and second stages 250, 252 of interior coil 212 may each be formed from suitable tubing. The tubing may be wound around separate support structures, e.g., such that first and second stages 250, 252 of interior coil 212 are spaced apart from each other within casing 110, or the tubing may be wound around a common support structure, e.g., such that first and second stages 250, 252 of interior coil 212 are positioned adjacent each other within casing 110, as will be understood by those skilled in the art.

As may be seen in FIGS. 2 and 3, sealed system 200 also includes a reversing valve 216. Reversing valve 216 selectively directs compressed refrigerant from compressor 210 towards either interior coil 212 or exterior coil 214. For example, in the cooling mode (shown in FIG. 2), reversing valve 216 is arranged or configured to direct compressed refrigerant from compressor 210 to or towards exterior coil 214. Conversely, in the heating mode (shown in FIG. 3), reversing valve 216 is arranged or configured to direct compressed refrigerant from compressor 210 to or towards second stage 252 of interior coil 212. Thus, reversing valve 216 permits sealed system 200 to adjust between the heating mode and the cooling mode, as will be understood by those skilled in the art.

As shown in FIG. 2, during operation of sealed system 200, compressor 210 operates to increase a pressure of refrigerant within the compressor 210. In particular, refrigerant from second stage 252 of interior coil 212 and vapor refrigerant from a phase separator 222 are directed to compressor 210 in the cooling mode. Vapor refrigerant from phase separator 222 may be a fluid in the form of a saturated or superheated vapor. Upon exiting first state 252 of interior coil 212 and phase separator 222, the refrigerant may enter compressor 210, and compressor 210 may operate to compress the refrigerant. Accordingly, the pressure and temperature of the refrigerant may be increased in compressor 210 such that the refrigerant becomes a more superheated vapor.

Exterior coil 214 is disposed downstream of compressor 210 in the cooling mode and acts as a condenser. Thus, exterior coil 214 is operable to reject heat into the exterior atmosphere, e.g., at exterior side portion 114 of casing 110, when sealed system 200 is operating in the cooling mode. For example, the superheated vapor from compressor 210 may enter exterior coil 214 via suitable conduit or piping that extends between and fluidly connects reversing valve 216 and exterior coil 214. Within exterior coil 214, the refrigerant from compressor 210 transfers energy to the exterior atmosphere and condenses into a saturated liquid, liquid vapor mixture and/or subcooled liquid. An exterior air handler or fan 230 positioned adjacent exterior coil 214 may facilitate or urge a flow of air from the exterior atmosphere across exterior coil 214 in order to facilitate heat transfer.

As may be seen in FIGS. 2 and 3, sealed system 200 also includes a phase separator 222 and an injector or ejector 232. Phase separator 222 is configured for separating liquid refrigerant within phase separator 222 from vapor refrigerant within phase separator 222, e.g., in the cooling mode. By separating liquid refrigerant from vapor refrigerant, phase separator 222 may improve a performance and/or efficiency of packaged terminal air conditioner unit 100, as discussed in greater detail below.

As shown in FIG. 2, in the cooling mode, phase separator 222 is fluidly coupled to exterior coil 214 via a supply conduit 234. Thus, supply conduit 234 may extend between and fluidly connect exterior coil 214 and phase separator 222 such that refrigerant from exterior coil 214 may flow through supply conduit 234 to phase separator 222. Ejector 232 is coupled to supply conduit 234 and is configured for introducing or injecting vapor refrigerant from first stage 250 of interior coil 212 into supply conduit 234. In particular, ejector 232 may be configured for combining streams of refrigerant via the Venturi effect. Ejector 232 is positioned on supply conduit 234 and receives vapor phase refrigerant from first stage 250 of interior coil 212 via a first distribution conduit 236 that extends between and fluidly connects first stage 250 of interior coil 212 and ejector 232. Ejector 232 directs or urges the vapor phase refrigerant from first distribution conduit 236 into supply conduit 234 and refrigerant flowing through supply conduit 234.

It should be understood that phase separator 222 may be any suitable type of phase separator. For example, phase separator 222 may be constructed in the same or similar manner to the phase separator described in U.S. patent application Ser. No. 14/088,558 of Brent Alden Junge and/or the phase separator described in U.S. patent application Ser. No. 14/258,397 of Brent Alden Junge et al., both of which are incorporated by reference herein for all purposes. Within a casing of phase separator 222, liquid phase refrigerant may collect or pool at a bottom portion of phase separator 222 and vapor phase refrigerant may collect or pool at a top portion of phase separator 222, e.g., due to density differences between the liquid and vapor phase refrigerants.

Sealed system 200 also includes a connection conduit 240. As may be seen in FIGS. 2 and 3, connection conduit 240 extends between phase separator 222 and second stage 252 of interior coil 212. In the cooling mode, phase separator 222 receives refrigerant from supply conduit 234 and separates liquid refrigerant from supply conduit 234 and vapor refrigerant from supply conduit 234. The liquid phase refrigerant within phase separator 222 is directed from phase separator 222 to second stage 252 of interior coil 212 via connection conduit 240, as shown in FIG. 2. Conversely, the vapor phase refrigerant within phase separator 222 is directed around second stage 252 of interior coil 212 back to compressor 210 such that the vapor phase refrigerant bypasses second stage 252 of interior coil 212 in the cooling mode. In particular, a bypass conduit 244 extends from phase separator 222 around second stage 252 of interior coil 212, and vapor phase refrigerant from phase separator 222 bypasses second stage 252 of interior coil 212 via bypass conduit 244 in the cooling mode.

A throttling device 220 is disposed on a second distribution conduit 242. Second distribution conduit 242 extends between exterior coil 214 and first stage 250 of interior coil 212. Throttling device 220 is positioned between exterior coil 214 and first stage 250 of interior coil 212 on second distribution conduit 242. In the cooling mode, refrigerant from exterior coil 214 travels through throttling device 220 before flowing through first stage 250 of interior coil 212. Throttling device 220 may generally expand the refrigerant, lowering the pressure and temperature thereof. Throttling device 220 (e.g., and any other throttling device described herein) may include various components for throttling refrigerant flow through second distribution conduit 242. For example, throttling device 220 (e.g., and any other throttling device described herein) may include a capillary tube and check valve, a J-T valve, an electronic expansion valve, etc. to throttle the flow of refrigerant through second distribution conduit 242, as will be understood by those skilled in the art.

First stage 250 of interior coil 212 is disposed downstream of throttling device 220 in the cooling mode and acts as an evaporator. Thus, first stage 250 of interior coil 212 is operable to heat refrigerant within first stage 250 of interior coil 212 with energy from the interior atmosphere, e.g., at interior side portion 112 of casing 110, when sealed system 200 is operating in the cooling mode. For example, within first stage 250 of interior coil 212, the refrigerant from throttling device 220 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. An interior air handler or fan 228 positioned adjacent first stage 250 of interior coil 212 may facilitate or urge a flow of air from the interior atmosphere across first stage 250 of interior coil 212 in order to facilitate heat transfer. As discussed above, ejector 232 directs the vapor refrigerant from interior coil 212 into supply conduit 234.

Like first stage 250 of interior coil 212, second stage 252 of interior coil 212 acts as an evaporator in the cooling mode; however, second stage 252 of interior coil 212 is disposed downstream of phase separator 222 in the cooling mode. Thus, second stage 252 of interior coil 212 is operable to heat refrigerant within second stage 252 of interior coil 212 with energy from the interior atmosphere, e.g., at interior side portion 112 of casing 110, when sealed system 200 is operating in the cooling mode. For example, within second stage 252 of interior coil 212, the liquid refrigerant from phase separator 222 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. Interior fan 228 positioned adjacent second stage 252 of interior coil 212 may facilitate or urge a flow of air from the interior atmosphere across second stage 252 of interior coil 212 in order to facilitate heat transfer.

During operation of sealed system 200 in the heating mode, reversing valve 216 reverses the direction of refrigerant flow through sealed system 200, as shown in FIG. 3. Thus, in the heating mode, first and second stages 250, 252 of interior coil 212 are disposed downstream of compressor 210 and each act as a condenser, e.g., such that first and second stages 250, 252 of interior coil 212 are operable to reject heat into the interior atmosphere at interior side portion 112 of casing 110.

As may be seen in FIG. 3, phase separator 222 and ejector 232 act as conduits to direct compressed refrigerant between first and second stages 250, 252 of interior coil 212 in the heating mode. A second check valve 226 on supply conduit 234 may block refrigerant flow from ejector 232 to exterior coil 214 via supply conduit 234 in the heating mode. A first check valve 224 on bypass conduit 244 may block refrigerant flow from reversing valve to phase separator 222 via bypass conduit 244, e.g., in the heating mode as shown in FIG. 3.

Exterior coil 214 is disposed downstream of throttling device 220 in the heating mode and acts as an evaporator. Thus, exterior coil 214 is operable to heat refrigerant within exterior coil 214 with energy from the exterior atmosphere, e.g., at exterior side portion 114 of casing 110, when sealed system 200 is operating in the heating mode. For example, within exterior coil 214, the refrigerant from throttling device 220 receives energy from the exterior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. From exterior coil 214, refrigerant is directed back to compressor 210.

Sealed system 200 may assist with operating packaged terminal air conditioner unit 100 efficiently. For example, ejector 232 of sealed system 200 may utilize expansion work of high-pressure refrigerant to compress vapor refrigerant exiting first stage 250 of interior coil 212 in the cooling mode. In such a manner, ejector 232 may assist with reducing energy consumption of compressor 210 in the cooling mode. Phase separator 222 also reduces a pressure drop in second stage 252 of interior coil 212 by bypassing vapor refrigerant directly to compressor 210 in the cooling mode.

FIGS. 4 and 5 provide schematic views of components of a sealed system 300 for a packaged terminal air conditioner unit according to another exemplary embodiment of the present subject matter. Sealed system 300 may be used with or in any suitable packaged terminal air conditioner unit. For example, sealed system 300 may be used in packaged terminal air conditioner unit 100 (FIG. 1) as sealed system 120. Sealed system 300 is shown operating in a cooling mode in FIG. 4, and sealed system 300 is shown operating in a heating mode in FIG. 5. The unlabeled arrows in FIGS. 4 and 5 indicate the direction of refrigerant flow within adjacent conduits or piping of sealed system 300 in the cooling mode and heating mode, respectively.

Like sealed system 200 (FIGS. 2 and 3), sealed system 300 generally operates in a heat pump cycle. Sealed system 300 includes similar components to sealed system 200 and operates in a similar manner. For example, sealed system 300 includes a compressor 310, an interior heat exchanger or coil 312 and an exterior heat exchanger or coil 314. Sealed system 300 also includes a reversing valve 316 that selectively directs compressed refrigerant from compressor 310 towards either interior coil 312 or exterior coil 314. Interior coil 312 is a split coil or heat exchanger and includes two separate or discrete stages, a first coil or stage 350 and a second coil or stage 352, and exterior coil 314 is also a split coil or heat exchanger and includes two separate or discrete stages, a first coil or stage 354 and a second coil or stage 356. As is generally understood, various conduits may be utilized to flow refrigerant between the various components of sealed system 300.

As shown in FIG. 4, during operation of sealed system 300, compressor 310 operates to increase a pressure of refrigerant within the compressor 310. In particular, vapor refrigerant from second stage 352 of interior coil 312 is directed to compressor 310 in the cooling mode. The vapor refrigerant may be a fluid in the form of a superheated vapor. Compressor 310 is operable to compress the refrigerant, e.g., such that the pressure and temperature of the refrigerant increase and the refrigerant becomes a more superheated vapor.

First stage 354 of exterior coil 314 is disposed downstream of compressor 310 in the cooling mode and acts as a condenser. Thus, first stage 354 of exterior coil 314 is operable to reject heat into the exterior atmosphere, e.g., at exterior side portion 114 of casing 110, when sealed system 300 is operating in the cooling mode. Within first stage 354 of exterior coil 314, the refrigerant from compressor 310 transfers energy to the exterior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture. An exterior air handler or fan 330 positioned adjacent first stage 354 of exterior coil 314 may facilitate or urge a flow of air from the exterior atmosphere across first stage 354 of exterior coil 314 in order to facilitate heat transfer.

Sealed system 300 also includes a first injector or ejector 332 and a second injector or ejector 334. As may be seen in FIG. 4, refrigerant from first stage 354 of exterior coil 314 flows through second ejector 334 to second stage 356 of exterior coil 314 in the cooling mode. Thus, second ejector 334 acts as a conduit to direct refrigerant from first stage 354 of exterior coil 314 to second stage 356 of exterior coil 314, in the cooling mode. Second stage 356 of exterior coil 314 is operable to reject heat into the exterior atmosphere, e.g., at exterior side portion 114 of casing 110, when sealed system 300 is operating in the cooling mode. Within second stage 356 of exterior coil 314, the refrigerant from first stage 354 of exterior coil 314 transfers energy to the exterior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture. Exterior fan 330 is positioned adjacent second stage 356 of exterior coil 314 and may facilitate or urge a flow of air from the exterior atmosphere across second stage 356 of exterior coil 314 in order to facilitate heat transfer.

First ejector 332 is disposed downstream of second stage 356 of exterior coil 314, in the cooling mode, and is configured for introducing or injecting vapor refrigerant from first stage 350 of interior coil 312 into the flow of refrigerant from second stage 356 of exterior coil 314. In particular, first ejector 332 may be configured for combining streams of refrigerant via the Venturi effect. Second stage 352 of interior coil 312 is positioned downstream of first ejector 332 and receives the combined flow of refrigerant from first ejector 332 in the cooling mode.

Sealed system 300 also includes various throttling devices and/or check valves. In particular, sealed system 300 includes a throttling device 338, a first check valve 346 and a second check valve 348. Throttling device 338 is disposed between second stage 356 of exterior coil 314 and first stage 350 of interior coil 312 in the cooling mode. In the cooling mode, refrigerant from second stage 356 of exterior coil 314 travels through throttling device 338 before flowing to first stage 350 of interior coil 312. Throttling device 338 may generally expand the refrigerant, lowering the pressure and temperature thereof. The refrigerant may then be flowed to first stage 350 of interior coil 312. In the cooling mode, second check valve 348 may hinder or prevent refrigerant from first stage 354 of exterior coil 314 from bypassing second stage 356 of exterior coil 314 and/or throttling device 338.

First stage 350 of interior coil 312 is disposed downstream of throttling device 338 in the cooling mode and acts as an evaporator. Similarly, second stage 352 of interior coil 312 is disposed downstream of first ejector 332 in the cooling mode and also acts as an evaporator. Thus, first and second stages 350, 352 of interior coil 312 are operable to heat refrigerant within interior coil 312 with energy from the interior atmosphere, e.g., at interior side portion 112 of casing 110, when sealed system 300 is operating in the cooling mode. For example, within first stage 350 of interior coil 312, the refrigerant from throttling device 338 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. Similarly, within second stage 352 of interior coil 312, the refrigerant from first ejector 332 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. An interior air handler or fan 328 positioned adjacent first and second stages 350, 352 of interior coil 312 may facilitate or urge a flow of air from the interior atmosphere across first and second stages 350, 352 of interior coil 312 in order to facilitate heat transfer.

During operation of sealed system 300 in the heating mode, reversing valve 316 reverses the direction of refrigerant flow through sealed system 300, as shown in FIG. 5. Thus, in the heating mode, second stage 352 of interior coil 312 is disposed downstream of compressor 310 and acts as a condenser. Second stage 352 of interior coil 312 is operable to reject heat into the interior atmosphere, e.g., at interior side portion 112 of casing 110, when sealed system 300 is operating in the heating mode. Within second stage 352 of interior coil 312, the refrigerant from compressor 310 transfers energy to the interior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture.

As may be seen in FIG. 5, refrigerant from second stage 352 of interior coil 312 flows through first ejector 332 to first stage 350 of interior coil 312 in the cooling mode. Thus, first ejector 332 acts as a conduit to direct refrigerant from second stage 352 of interior coil 312 to first stage 350 of interior coil 312, in the heating mode. First stage 350 of interior coil 312 is operable to reject heat into the interior atmosphere, e.g., at interior side portion 112 of casing 110, when sealed system 300 is operating in the heating mode. Within first stage 350 of interior coil 312, the refrigerant from second stage 352 of interior coil 312 transfers energy to the interior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture.

Second ejector 334 is disposed downstream of first stage 350 of interior coil 312, in the heating mode, and is configured for introducing or injecting vapor refrigerant from second stage 356 of exterior coil 314 into the flow of refrigerant from first stage 350 of interior coil 312. In particular, second ejector 334 may be configured for combining streams of refrigerant via the Venturi effect. First stage 354 of exterior coil 314 is positioned downstream of second ejector 334 and receives the combined flow of refrigerant from second ejector 334 in the heating mode.

Throttling device 338 is disposed between first stage 350 of interior coil 312 and second stage 356 of exterior coil 314 in the heating mode. In the heating mode, refrigerant from first stage 350 of interior coil 312 travels through throttling device 338 before flowing to second stage 356 of exterior coil 314. Throttling device 338 may generally expand the refrigerant, lowering the pressure and temperature thereof. The refrigerant may then be flowed to second stage 356 of exterior coil 314. In the heating mode, first check valve 346 may hinder or prevent refrigerant from second stage 352 of interior coil 312 from bypassing first stage 350 of interior coil 312 and/or throttling device 338.

Second stage 356 of exterior coil 314 is disposed downstream of throttling device 338 in the heating mode and acts as an evaporator. Similarly, first stage 354 of exterior coil 314 is disposed downstream of second ejector 334 in the heating mode and also acts as an evaporator. Thus, first and second stages 354, 356 of exterior coil 314 are operable to heat refrigerant within exterior coil 314 with energy from the exterior atmosphere, e.g., at exterior side portion 114 of casing 110, when sealed system 300 is operating in the heating mode. For example, within second stage 356 of exterior coil 314, the refrigerant from throttling device 338 receives energy from the exterior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture. Similarly, within first stage 354 of exterior coil 314, the refrigerant from second ejector 334 receives energy from the exterior atmosphere and vaporizes into superheated vapor and/or high quality vapor-liquid mixture.

Sealed system 300 may assist with operating packaged terminal air conditioner unit 100 efficiently. For example, first and second ejectors 332, 334 of sealed system 300 may utilize expansion work of high-pressure refrigerant to compress vapor refrigerant exiting first stage 350 of interior coil 312 in the cooling mode and second stage 356 of exterior coil 314 in the heating mode. In such a manner, first and second ejectors 332, 334 may assist with reducing energy consumption of compressor 310 in the cooling and heating modes.

FIGS. 6 and 7 provide schematic views of components of a sealed system 400 for a packaged terminal air conditioner unit according to another exemplary embodiment of the present subject matter. Sealed system 400 may be used with or in any suitable packaged terminal air conditioner unit. For example, sealed system 400 may be used in packaged terminal air conditioner unit 100 (FIG. 1) as sealed system 120. Sealed system 400 is shown operating in a cooling mode in FIG. 6, and sealed system 400 is shown operating in a heating mode in FIG. 7. The unlabeled arrows in FIGS. 6 and 7 indicate the direction of refrigerant flow within adjacent conduits or piping of sealed system 400 in the cooling mode and heating mode, respectively.

Like sealed system 300 (FIGS. 5 and 6), sealed system 400 generally operates in a heat pump cycle. Sealed system 400 includes similar components to sealed system 300 and operates in a similar manner. For example, sealed system 400 includes a compressor 410, an interior heat exchanger or coil 412 and an exterior heat exchanger or coil 414. Sealed system 400 also includes a reversing valve 416 that selectively directs compressed refrigerant from compressor 410 towards either interior coil 412 or exterior coil 414. As is generally understood, various conduits may be utilized to flow refrigerant between the various components of sealed system 400. Also, interior coil 412 is a split coil or heat exchanger and includes two separate or discrete stages, a first coil or stage 450 and a second coil or stage 452, and exterior coil 414 is also a split coil or heat exchanger and includes two separate or discrete stages, a first coil or stage 454 and a second coil or stage 456. Sealed system 400 further includes a first injector or ejector 432, a second injector or ejector 434, an expansion device 438, a first check valve 446 and a second check valve 448.

Sealed system 400 also includes a first phase separator 422, a second phase separator 424, a third check valve 447 and a fourth check valve 449. First and second phase separators 422, 424 are configured for separating liquid refrigerant within first and second phase separators 422, 424 from vapor refrigerant within first and second phase separators 422, 424.

In the cooling mode, second phase separator 424 receives refrigerant from second ejector 434 and separates liquid refrigerant from vapor refrigerant. The liquid phase refrigerant within second phase separator 424 is directed from second phase separator 424 to second stage 452 of interior coil 412. Conversely, the vapor phase refrigerant within second phase separator 424 is directed around second stage 452 of interior coil 412 back to compressor 410 such that the vapor phase refrigerant bypasses second stage 452 of interior coil 412 in the cooling mode. As may be seen in FIG. 6, refrigerant from first stage 454 of exterior coil 414 flows through first phase separator 422 and first ejector 432 to second stage 456 of exterior coil 414 in the cooling mode. Thus, first phase separator 422 and first ejector 432 act as a conduit to direct refrigerant from first stage 454 of exterior coil 414 to second stage 456 of exterior coil 414, in the cooling mode. Third check valve 447 may block compressed refrigerant from bypassing exterior coil 414 in the cooling mode.

In the heating mode, first phase separator 422 receives refrigerant from first ejector 432 and separates liquid refrigerant from vapor refrigerant. The liquid phase refrigerant within first phase separator 422 is directed from first phase separator 422 to first stage 454 of exterior coil 414. Conversely, the vapor phase refrigerant within first phase separator 422 is directed around first stage 454 of exterior coil 414 back to compressor 410 such that the vapor phase refrigerant bypasses first stage 454 of exterior coil 414 in the heating mode. As may be seen in FIG. 7, refrigerant from second stage 452 of interior coil 412 flows through second phase separator 424 to first stage 454 of interior coil 412 in the heating mode. Thus, second phase separator 424 acts as a conduit to direct refrigerant from second stage 452 of interior coil 412 to first stage 454 of interior coil 412, in the heating mode. Fourth check valve 449 may block compressed refrigerant from bypassing interior coil 412 in the heating mode.

Sealed system 400 may assist with operating packaged terminal air conditioner unit 100 efficiently. For example, first and second ejectors 432, 434 of sealed system 400 may utilize expansion work of high-pressure refrigerant to compress vapor refrigerant exiting first stage 450 of interior coil 412 in the cooling mode and second stage 456 of exterior coil 414 in the heating mode. In such a manner, first and second ejectors 432, 434 may assist with reducing energy consumption of compressor 410 in the heating and cooling modes. First and second phase separators 422, 424 also reduce a pressure drop in second stage 452 of interior coil 412 and first stage 454 of exterior coil 414 by bypassing vapor refrigerant directly to compressor 410 in the heating and cooling modes.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A packaged terminal air conditioner unit, comprising: a casing; a compressor positioned within the casing, the compressor operable to increase a pressure of a refrigerant; an interior heat exchanger positioned within the casing, the interior heat exchanger having a first stage and a second stage; an exterior heat exchanger positioned within the casing opposite the interior heat exchanger; a phase separator positioned within the casing, the phase separator configured for separating liquid refrigerant from vapor refrigerant; a reversing valve positioned within the casing, the reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor, the reversing valve configured for selectively directing the compressed refrigerant from the compressor to the exterior heat exchanger or the second stage of the interior heat exchanger; a supply conduit extending between the exterior heat exchanger and the phase separator; an ejector coupled to the supply conduit; a first distribution conduit extending between the first stage of the interior heat exchanger and the ejector; a second distribution conduit extending between the exterior heat exchanger and the first stage of the interior heat exchanger; a connection conduit extending between the phase separator and the second stage of the interior heat exchanger; and a bypass conduit extending from the phase separator around the second stage of the interior heat exchanger.
 2. The packaged terminal air conditioner unit of claim 1, further comprising a check valve coupled to the supply conduit, the check valve positioned between the exterior heat exchanger and the ejector on the supply conduit.
 3. The packaged terminal air conditioner unit of claim 1, further comprising a throttling device coupled to the second distribution conduit, the throttling device positioned between the exterior heat exchanger and the first stage of the interior heat exchanger on the second distribution conduit.
 4. The packaged terminal air conditioner unit of claim 3, wherein the throttling device is a capillary tube.
 5. The packaged terminal air conditioner unit of claim 1, further comprising a check valve coupled to the bypass conduit, the check valve positioned between the phase separator and the reversing valve on the bypass conduit.
 6. The packaged terminal air conditioner unit of claim 5, wherein the throttling device is a capillary tube.
 7. The packaged terminal air conditioner unit of claim 1, wherein in a cooling mode, a flow of liquid refrigerant from the exterior heat exchanger flows through the ejector such that the ejector draws vapor refrigerant from the first distribution conduit into the flow of liquid refrigerant and a combined flow of liquid and vapor refrigerant flows from the ejector to the phase separator, liquid refrigerant from the phase separator flowing to the second stage of the interior heat exchanger via the connection conduit in the cooling mode.
 8. The packaged terminal air conditioner unit of claim 7, wherein vapor refrigerant from the phase separator flows around the second stage of the interior heat exchanger via the bypass conduit in the cooling mode.
 9. The packaged terminal air conditioner unit of claim 1, wherein, in a heating mode, refrigerant from the second stage of the interior heat exchanger flows through the phase separator and the ejector to the first stage of the interior heat exchanger.
 10. A packaged terminal air conditioner unit, comprising: a casing extending between an exterior side portion and an interior side portion; a compressor positioned within the casing, the compressor operable to compress a refrigerant; an interior heat exchanger positioned within the casing at the interior side portion of the casing, the interior heat exchanger having a first stage and a second stage that are separate from each other; an exterior heat exchanger positioned within the casing at the exterior side portion of the casing; a reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor; a phase separator positioned within the casing, the phase separator configured for separating liquid refrigerant from vapor refrigerant; and an ejector positioned within the casing; wherein, the packaged terminal air conditioner unit is configured such that, in a cooling mode, a flow of liquid refrigerant from the exterior heat exchanger flows through the ejector and the ejector draws vapor refrigerant from the first stage of the interior heat exchanger into the flow of liquid refrigerant and a combined flow of liquid and vapor refrigerant flows from the ejector to the phase separator, vapor refrigerant from the phase separator flowing around the second stage of the interior heat exchanger to the compressor and liquid refrigerant from the phase separator flowing to the second stage of the interior heat exchanger in the cooling mode; and the packaged terminal air conditioner unit is also configured such that, in a heating mode, refrigerant from the second stage of the interior heat exchanger flows through the phase separator and the ejector to the first stage of the interior heat exchanger.
 11. The packaged terminal air conditioner unit of claim 10, further comprising a check valve coupled to a conduit that extends between the exterior heat exchanger and the ejector.
 12. The packaged terminal air conditioner unit of claim 10, further comprising a throttling device coupled to a conduit that extends between the exterior heat exchanger and the first stage of the interior heat exchanger.
 13. The packaged terminal air conditioner unit of claim 12, wherein the throttling device is a capillary tube.
 14. The packaged terminal air conditioner unit of claim 10, further comprising a check valve coupled to a conduit that extends between the phase separator and the reversing valve around the second stage of the interior heat exchanger.
 15. The packaged terminal air conditioner unit of claim 14, wherein the throttling device is a capillary tube.
 16. The packaged terminal air conditioner unit of claim 10, wherein the first and second stages of the interior heat exchanger are spaced apart from each other within the casing.
 17. The packaged terminal air conditioner unit of claim 10, wherein the first and second stages of the interior heat exchanger are positioned adjacent each other within the casing. 